Structure of the pre-60S ribosomal subunit with nuclear export factor Arx1 bound at the exit tunnel

• Verfasst von: Bradatsch, Bettina [VerfasserIn]
• Verfasst von: Gnädig, Marén [VerfasserIn]
• Verfasst von: Hurt, Ed [VerfasserIn]
• Titel: Structure of the pre-60S ribosomal subunit with nuclear export factor Arx1 bound at the exit tunnel
• Verf.angabe: Bettina Bradatsch, Christoph Leidig, Sander Granneman, Marén Gnädig, David Tollervey, Bettina Böttcher, Roland Beckmann & Ed Hurt
• Umfang: 8 S.
• Fussnoten: Published online 11 November 2012 ; Gesehen am 11.06.2018
• Titel Quelle: Enthalten in: Nature structural & molecular biology
• Jahr Quelle: 2012
• Band/Heft Quelle: 19(2012), 12, S. 1234-1241
• ISSN Quelle: 1545-9985
• DOI: doi:10.1038/nsmb.2438
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1576226484

Abstract

Preribosomal particles evolve in the nucleus through transient interaction with biogenesis factors before export to the cytoplasm. Here, we report the architecture of the late pre-60S particle, purified from Saccharomyces cerevisiae, through Arx1, a nuclear export factor with structural homology to methionine aminopeptidases, or its binding partner Alb1. Cryo-EM reconstruction of the Arx1 particle at 11.9-Å resolution reveals regions of extra density on the pre-60S particle attributed to associated biogenesis factors, confirming the immature state of the nascent subunit. One of these densities could be unambiguously assigned to Arx1. Immunoelectron microscopy and UV cross-linking localize Arx1 close to the ribosomal exit tunnel, in direct contact with ES27, a highly dynamic eukaryotic rRNA expansion segment. The binding of Arx1 at the exit tunnel may position this export factor to prevent premature recruitment of ribosome-associated factors active during translation.